I like to not only watch the instructors in those classes but also the participants - it gives me an idea for how well people are following along and how much "messing up" is happening. The participants are primarily women but today I noticed a guy doing Zumba right in the front row.
Or, well, maybe he wasn't doing Zumba. I'm not sure what you would call those moves. There were random kicks and punches, Snoopy dancing, Chippendale thrusts, and spins. None of these were even close to what the rest of the class was doing.
Either this guy is my hero for getting an amazing cardio workout without being self-conscious about his lack of, umm, Zumba skills, or he was getting an amazing cardio workout by being in the front row and watching the instructor. By law (or not), Zumba instructors seem to have two important features - a nice round booty and a good amount of cleavage. This instructor probably graduated at the top of her class based on those criteria and I find it hard to believe this was lost on Mr. Zumba. Either way, I'm sure his heart rate was sufficiently elevated to burn a few calories.